Shaver cutter head

ABSTRACT

An improved inner cutter for a shaver of the type which includes a cutter head having an outer cutter, an inner cutter, and a spring having opposite end portions which are adapted to be detachably connected to the inner cutter for reciprocating the inner cutter within the outer cutter. The spring is adapted to be urged from a relaxed state to a compressed state. The inner and outer cutters each include a hair shearing edge, the hair shearing edge of the inner cutter being urged, by means of the compressed spring, to cooperate with the hair shearing edge of the outer cutter for shearing hair as the inner cutter is reciprocated within the outer cutter. To promote ease of assembly of the inner cutter and spring, a wall of the improved inner cutter is provided with spaced apertures, each of which is dimensioned to loosely receive therein one of the end portions of the spring. In addition, a surface of the inner cutter wall is provided with a recess having convergent walls. The recess is dimensioned to wedge one of the spring end portions within the recess when the spring is in its compressed state. The spring is thus firmly connected to the inner cutter when reciprocating the inner cutter within the outer cutter.

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Locke [451 May 14, 11974 SHAVER CUTTER HEAD [75] Inventor: David R. Locke, Bridgeport, Conn.

[73] Assignee: Sperry Rand Corporation,

Bridgeport, Conn.

[22] Filed: Jan. 111, 1973 [21] Appl. No.: 322,760

[52] US. O! BIO/43.92, 30/346.5l, 403/121 Primary Examiner-Al Lawrence Smith Assistant Examiner-Gary L. Smith Attorney, Agent, or FirmCharles R. Miranda; Donald P. Walker [57] ABSTRACT An improved inner cutter for a shaver of the type which includes a cutter head having an outer cutter, an inner cutter, and a spring having opposite end portions which are adapted to be detachably connected to the inner cutter for reciprocating the inner cutter within the outer cutter. The spring is adapted to be urged from a relaxed state to a compressed state. The inner and outer cutters each include a hair shearing edge, the hair shearing edge of the inner cutter being urged, by means of the compressed spring, to cooperate with the hair shearing edge of the outer cutter for shearing hair as the inner cutter is reciprocated within the outer cutter. To promote ease of assembly of the inner cutter and spring, a wall of the improved inner cutter is provided with spaced apertures, each of which is dimensioned to loosely receive therein one of the end portions of the spring. In addition, a surface of the inner cutter wall is provided with a recess having convergent walls. The recess is dimensioned to wedge one of the spring end portions within the recess when the spring is in its compressed state. The spring is thus firmly connected to the inner cutter when reciprocating the inner cutter within the outer cutter.

13 Claims, 14 Drawing Figures SHEET 1 BF 3 PATENVEB MAY 14 m4 F0 5 Z2 M 55 i M M 'Z Pmmtmm .14 mm 3310 30s saw 3 or 3 1 SHAVER CUTTER HEAD BACKGROUND OF THE INVENTION This invention is concerned with an electric shaver having an improved inner cutter of the type which is adapted to be reciprocated within an outer cutter by means of a spring having an end thereof connected to the inner cutter. More particularly, the invention is concerned with an inner cutter of the aforesaid type which is adapted to loosely carry said spring when the spring is in its relaxed state, and which includes a surface provided with a recess having a wall configuration adapted for wedging said end of the spring within the recess when the spring is in its compressed state.

The invention is generally adaptable to shavers of the type which include one or more outer cutters and a corresponding number of inner cutters, wherein each of the cutters is provided with a hair shearing edge and the inner cutters are mounted for reciprocation within the outer cutters for shearing hair.

A typical cutter head of the aforesaid type includes one or more hollow, elongated, outer cutters, which are rectangular in transverse cross-section, and a corresponding number of elongated inner cutters mounted for reciprocation within the outer cutters. Each of the outer cutters includes an upper wall, depending skirt walls and a base spacer. The upper walls are each provided with plural hair reception slots which form a plurality of parallel hair shearing teeth, having hair shearing edges, in the upper wall. Each of the inner cutters includes an upper wall, depending side walls and a lower wall. The upper walls of the respective inner cutters are provided with hair shearing teeth forming hair shearing edges therein. The hair shearing edges of the inner cutter are disposed tocooperate with the hair shearing edges of the outer cutter for shearing hairs which enter the hair reception slots, as the inner cutter is reciprocated within the outer cutter. The inner cutters are reciprocated within the respective outer cutters by means of a that spring having opposite end portions and a mid-portion, the opposite end portions of each spring being connected to an inner cutter and the midportion being driven by a motor mounted within the shaver. 7

An example of a typical cutter head as hereinbefore described is disclosed in US. Pat. No. 2,793,430 issued to Carissimi, Jan. 26, 1955. As disclosed in said Patent, a flat spring having an end portions rigidly connected to the inner cutter, is provided for driving each of the inner cutters. The springs each include a partial loop formed therein, midway between the end portions of the spring, to engage a motor arm oscillated by the motor of the shaver. The motor arms, and thus the springs and inner cutters, are reciprocated by the motor several hundred times per minute. To promote rapid assembly of the inner cutters and springs, and to avoid costly select fitting procedures, the inner cutters are preferably constructed to allow for loosely connecting a randomly chosen spring thereto. On the other hand, a loose connection between an inner cutter and spring allows for movement between the spring and inner cutter when the shaver is operated. Since such movement causes noise to be emitted by the cutter head, and causes the inner cutters, springs, and other parts of the cutter head, to wear too rapidly, it is preferred that the inner cutter and spring be firmly connected to one another .when the shaver is operated.

Accordingly, an object of this invention is to provide an improved inner cutter for a cutter head of an electric shaver.

Another object is to provide an inner cutter including means for loosely connecting a spring thereto when the spring is in its relaxed state, and means for firmly connecting the spring thereto when the spring is in its compressed state.

And, another object is to provide an improved cutter head including an inner cutter for an electric shaver, wherein the inner cutter is adapted to have a spring loosely connected thereto when the spring is in its relaxed state, and wherein the inner cutter is provided with means for wedging an end of the spring thereagainst when the spring is in its compressed state.

SUMMARY OF THE INVENTION The invention resides in providing an improved inner cutter for a shaver of the type which includes a spring, having opposite end portions which are detachably connectable to the inner cutter. The shaver includes an outer cutter within which the inner cutter is normally mounted for reciprocation and wherein the inner cutter is reciprocated by means of the spring. The outer cutter includes a hair shearing edge, and the inner cutter includes a hair shearing edge which is urged, due to the spring being urged from a relaxed state to a compressed state, to cooperate with the hair shearing edge of the outer cutter for shearing hair as the inner cutter is reciprocated within the outer cutter. The improved inner cutter includes an aperture which is dimensioned to loosely receive therein one of the end portions of the relaxed spring, when connecting the inner cutter and spring, and a recess having a wall configuration adapted to wedge the spring end portion within the re cess when the spring is-in its compressed state. The relaxed spring is thus loosely connectable to the inner cutter, but when compressed, is firmly connected to the inner cutter, but when compressed, is firmly connected to the inner cutter for reciprocating the inner cutter within the outer cutter.

BRIEF'DESCRIPTION OF DRAWINGS which are adapted to be included in the cutter head of FIG. 1;

FIG. 4 is a partial cross-sectional view, in elevation, of the lower wall of an inner cutter, showing a relaxed spring connected to the lower wall;

FIG. 5 is a partial cross-sectional view, in elevation, of an inner cutter and spring mounted within an outer cutter to form an assembled cutter head.

FIG. 6 is a partial cross-sectional view, in elevation, of the lower wall of an inner cutter, showing a compressed spring connected to the lower wall;

FIG. 7 is an exploded, partial, perspective view of an inner cutter and spring, showing the lower wall of an inner cutter in accordance with the invention;

FIG. 8 is a partial bottom plan view of the lower wall of the inner cutter of FIG. 7;

FIG. 9 is a cross-sectional view, in elevation, of the inner cutter of FIG. 8, taken substantially along the line 9-9 of FIG. 8;

FIG. 10 is a cross-sectional view, in elevation, of the inner cutter of FIG. 8, taken substantially along the line 1010 of FIG. 8;

FIG. 11 is a cross-sectional end view of the inner cutter and spring of FIG. 7, taken substantially along the line 1l-11 of FIG. 7;

FIG. 12 is a partial cross-sectional view in elevation of the inner cutter and spring of FIG. 7, connected in accordance with the invention;

FIG. 13 is an exploded perspective view of the upper end of another type of electric shaver, including a cutter head having an inner cutter which may be modified to include the invention, the inner cutter being shown removed from the cutter head; and

FIG. 14 is an enlarged, exploded, perspective view of a type of inner cutter, and spring therefor, adapted to be included in the cutter head of FIG. 13, wherein the inner cutter is constructed in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, an upper end of an electric dry shaver 10 (FIG. 1), of the type in which the invention may be included, generally includes an upper portion of a casing 11. The casing 11 includes spaced front and rear walls, respectively numbered 12 and 13, and spaced side walls 14. The walls 12, 13 and 14 define a rectangularly-shaped receptacle 15 within which a cutter head 16 is located.

The cutter head 16 includes a plurality of hollow, elongated, stationary, outer cutters 17, which are rectangular in transverse cross-section. Each of the outer cutters 17 has an upper wall 18, spaced depending skirt walls 19, and an elongated base spacer 20 having a U- shaped appearance in transverse cross-section. The outer cutters 17 each have hair shearing means including two rows of a plurality of spaced, parallel, transversely extending, hair shearing teeth 21 formed by two rows of hair reception slots 22 spaced from one another by a substantially U-shaped channel 23 in the upper wall portion 18 of the outer cutter 17. The hair shearing teeth 21 respectively include opposed hair shearing edges 24. Each of the base spacers 20 has opposed ends 25 and a rectangularly-shaped aperture 26 formed therein. The apertures 26 are located approximately midway between the opposed ends 25 of the respective base spacers 20. The base spacers 20 are positioned between the lower ends of the skirt portions 19 of the respective outer cutters l7, and fixedly connected to the skirt portions 19 by means well-known in the art, for example, as by welding.

The outer cutters 17 are mounted alongside and parallel to one another on a cutter head mounting frame 28. The frame 28 includes an elongated, rectangular, base plate 29 having a plurality of spaced, parallel, apertures 30 formed therein, and a plurality depending leg portions 31. The outer cutter base spacer apertures 26 are respectively aligned in registry with one of the frames base plate apertures 30, and the base spacers 20 are fixedly connected to the base plate 29 of the frame 28, by means well-known in the art. For example, the base plate 29 may be provided with tabs 32, which are folded over the ends 25 of the outer cutter base spacers 20. The leg portions 31 may be removably fastened, by well-known means (not shown), to a motor housing 33 within the casing 11.

The cutter head 16 also includes a plurality of hollow, elongated, movable inner cutters 35 (FIGS. 1 and 2), which are rectangular in transverse cross-section. Alternatively, as shown in FIG. 3, the cutter head 16 may include a plurality of inner cutters 35 having a substantially U-shaped appearance in transverse crosssection. In either instance, each of the inner cutters 35 (FIGS. 2 and 3) has an upper wall 36 spaced depending side walls 37, and an elongated lower wall 38. The inner cutters 35 each have hair shearing means including two rows of a plurality of spaced, parallel, transversely oriented, hair shearing teeth 39, formed by two rows ofslots 40 separated from one another by a U- shaped channel 41. The hair shearing teeth 39 respectively include opposed hair shearing edges 42.

As shown in FIGS. 2 and 3, the inner cutter lower walls 38 are elongated, flat, substantially rectangularlyshaped portions of the inner cutter 35. The lower walls 38 respectively have opposed ends 47 and opposed inner and outer surfaces, respectively designated 48 and 49. An imaginary line 50 extending through the ends 47 of the respective lower walls 38, and which is located approximately equidistantly between the inner and outer surfaces, 48 and 49, and approximately equidistantly between the inner cutter side walls 37, is hereinafter referred to as the longitudinally extending centerline 50 of a given lower wall 38. Each of the lower walls 38 has a substantially rectangularly-shaped aperture 51 formed therein. The apertures 51 are located approximately midway between the opposed ends 47 of the respective lower walls 38. In addition, each of the lower walls 38 includes a keyhole-shaped aperture 52, located near one of the ends 47 of the wall 38. The keyhole-shaped aperture 52 includes a wide portion 54 and a narrow portion 55, the narrow portion 55 communicating with the wide portion 54. Each of the lower walls 38 also includes a substantially rectangularly-shaped aperture 56, located near the other end 47 of wall 38. Apertures 52 and 56 are spaced apart from one another and located on either side of aperture 51.

Each of the inner cutters 35 is reciprocated within one of the outer cutters 17 (FIG. 1), by means of a spring 57. The springs 57 are respectively driven by a motor arm 58 (FIGS. 1 and 5) of a shaver motor (not shown) mounted within the shaver motor housing 33. As shown in FIGS. 2 and 3, each of the springs 57 is a flat spring made of, for example, a flat strip of metal, metallic material of alloy. Each of the springs 57 is rectangularly-shaped in transverse cross-section, and has a body portion 60 and spaced end portions 61. The body portions 60 are'each provided with a partial loop 62, formed therein approximately midway between the spring end portions 61. Each of the body portions 60 has opposed upper and lower surfaces, respectively designated 63 and 64. The respective end portions 61 extend upwardly of, and approximately perpendicular to, the upper surfaces 63. One of the end portions 61 of each spring 57 is reduced in width and bent, to form a bent tang 65 and spaced shoulders 66. The opposite end portion 61 is reduced in width and notched, to form a T-shaped head 67 having opposed notches 68. The notches 68 each include opposed upper edges 69 and opposed lower edges 70.

The spring end portions 61 act as legs for connecting the springs 57 to the inner cutters 35 (FIGS. 2 and 3). As shown in FIG. 4, for ease of assembly of inner cutters 35 and springs 57, apertures 56 and 52 are respectively dimensioned to loosely receive and contain a springs tang 67 and T-shaped head 67. A given spring 57 is connected to an inner cutters lower wall 38 by first inserting the tang 65 into the rectangular-shaped aperture 56. The spring 57 is then bowed, thereby moving the loop 62 (FIGS. 2 and 3) away from the lower wall 38, to move the T-shaped head 67 slightly towards the tang 65. The T-shaped head 67 is then inserted into the keyhole apertures wide portion 54, as shown in dot-dash lines in FIG. 4. Upon releasing the spring 57, the T-shaped head 67 moves into the keyhole apertures narrow portion 55, as indicated by the arrow 71 in FIG. 4.

When the spring 57 is thus received within apertures 56 and 52, the spring 57 is in its relaxed state and is loosely, rather than rigidly, connected to the inner cutter 35. The spring end portions 61 extend through the apertures 56 and 52 and loosely rest on the lower wall 38. The spring 57 is normally loosely carried by the inner cutter 35 beneath the lower wall surface 49. The bent end of the springs tang 65 overhangs the inner surface 48 of wall 38 to rest on an adjacent area of the inner surface 48. The Springs shoulders 66, one of which is shown in FIG. 4, are spaced apart from the outer surface 49. In addition, the springs T-shaped head 67 overhangs the inner surface 49 of the wall 38, to rest the springs upper notchedges 69, one of which is shown in FIG. 4, on adjacent areas of the inner surface 48; and the T-shaped heads lower notch edges 70 are spaced apart from the outer surface 49.

Assuming inner cutters 35 (FIG. 1) and connected springs 57 are inserted within each of the outer cutters l7 (FIG-1), and the cutter head 16 is mounted within the shaver casing 11, the springs 57 (FIG. 5) are each compressed towards the associated inner cutter lower wall 38 by one of the shaver motor arms 58. The motor arms 58 extend upwardly through the outer cutter and mounting frame apertures, 26 and 30, and engage the spring loops 62 to compress the spring 57. When the shaver motor (not shown) is operated, reciprocating motion of the motor arms 58 results in each of springs 57 reciprocating one of the inner cutter 35.

As shown in FIG. 6, compression of the spring 57 toward the inner cutter lower wall 38, causes the springs end portions 61 to be inserted further inwardly of apertures 52 and 56. The bent end of the tang 65 is then spaced above the walls inner surface 48 and the spring shoulders'66, one of which is shown in FIG. 6, then bear against the outer surface 49. In addition, the T-shaped head s upper notch edges 69, one of which is shown in FIG. 6, are spaced above the walls inner surface 48, and the lower notch edges 70 now bear against the outer surface 49.

As shown in FIG. 5, when the tang 65 reciprocates the inner cutter 35 within the outer cutter 17, since the dimensions of the rectangularly-shaped aperture 56 (FIG. 6) are slightly larger than dimensions of the tang 65, the tang 65 freely moves relative to the inner cutter wall 38, the tang alternately contacting the opposed longitudinally extending side walls'of the aperture 56. As the tang 65 moves to and fro within aperture 56, the spring shoulders 66 slide against the outer surface 49. The sliding motion is accompanied by the shoulders 66 rocking on surface 49, toward and away from the adjacent end 47 of wall 38. Concurrently, the T-shaped head 67 slidably moves within keyhole aperture 52, the

T-shaped heads lower notch edges 70 slidably moving against the lower walls outer surface 49, as the spring 57 is reciprocated.

As a consequence ofthe allowable relative movement between the tang 65 and the inner cutter 35 as the shaver in operated, the inner cutters 35, springs 57, and other parts of the cutter head 16, tend to emit noise. However, this invention is directed to providing an inner cutter 35 including the aforesaid feature or dimensioning the aperture 56 to loosely contain an end portion of the spring 57, in combination with means for firmly connecting the-spring 57 and inner cutter 35 when the spring 57 is urged from its relaxed state to a compressed state. Normally this occurs when the inner cutter 35 and connected spring 57 are mounted within the outer cutter 17 for reciprocation therein, since the spring 57 is then urged toward the inner cutter 35 by means of the shaver motor arm 58. In the inventive construction the aforesaid relative movement between the tang 65 and inner cutter 35, as the shaver is operated, is substantially if not completely prevented. To

that end, as shown in FIG. 7, the outer surface 49 of the cutter wall 38, is additionally provided with recess 75. The recess has a wall configuration adapted to wedge the spring 57 within the recess 75 when the spring 57 is in its compressed state to thereby firmly connect the spring 57 to the inner cutter 35 for reciprocating the inner cutter 35 within the outer cutter 17 (FIG. 1).

The recess 75 (FIG. 7) has a mid-portion 76 which communicates with the rectangularly-shaped aperture 56, and has a rectangularly-shaped entry opening 77. In effect, the aperture 56 thus has an entry opening 77 which is elongated and set back within the wall 38 to form the recess 75. The recess 75 thus extends across aperture 56, transversely of centerline 50 and from the outer surface 49 towards the inner surface 48. The recess 75 has relatively convergent longitudinally extending, side walls, 80 and 81, opposed end walls 82 and a base wall 83. Side wall 80, the recess wall located closest to the adjacent end 47 of lower wall 38, merges with one of the longitudinally extending side walls of the rectangularly-shaped aperture 56, and side wall 81, the recess wall farthest from the adjacent end 47, merges with the opposite longitudinally extending side wall of aperture 56.

As shown in FIGS. 8-10 recess walls 80 and 81 lie in opposed inclined planes forming acute angles a and 1; relative to the outer surface 49. Although acute angle a, the acute angle between the plane of recess wall 80 and surface 49, is smaller than acute angle b, the acute angle between the plane of recess wall 81 and surface 49, this feature is not essential to the invention. The recess side walls, 80 and 81, approach one another more closely with increasing recess depth as measured from the recess entry opening 77. The recess 75 has a wedgeshaped wall configuration in transverse cross-section.

The side walls 80 and 81, and end walls 82, merge with the recess base wall 82 within the inner cutter wall 38, forming a recess 75 having a truncated wedge shape in transverse cross-section (FIGS. 9 and 10).

As shown in FIGS. 11 and 12, the lower wall aperture 56 and communicating recess 75 are dimensioned to loosely receive and contain therein the tang end portion 61 of one of the relaxed springs 57. To connect a given spring 57 to the inner cutter 35, the tang 65 is inserted through the recess entry opening 77 and into aperture 56. The spring 57 is thereafter connected to inner cutter 35 as previously described in connection with FIG. 4. The spring 57 is bowed to insert the T- shaped head 67 into the keyhole apertures wide portion 54, and released after insertion to allow the T- shaped head 67 to move into the keyhole apertures narrow portion 55.

When the spring 57 is in its relaxed state, the spring 57 is loosely carried by the inner cutter 35 beneath the inner cutters lower wall 38 as previously described in connection with FIG. 4. The aperture 56 is dimensioned to permit the tang 65 to freely contact the opposed side walls of aperture 56 when the spring 57 is in its relaxed state. However, when inner cutter 35 and spring 57, as described in connection with FIGS. 712, are mounted within an outer cutter 17, as shown in FIG. 5, and the spring 57 is compressed towards the lower wall 38 for reciprocation by the shaver motor arm 58, the springs tang 65 is inserted further inwardly of the recess 75. The tang 65 and the walls of aperture 56 cooperate with one another to align the spring shoulders 66, one of which is shown in FIG. 12, with the recess 75 for engagement of the shoulders 66 and recess walls 80 and 81. The shoulders 66 thus contact the recess side walls, 80 and 81, rather than the cutters outer surface 49 as shown in FIG. 6, and shoulder 66 are thus disposed within the inner cutter wall 38, rather than externally thereof. Also, as shown in FIG. 12, the shoulders 66 hold the tang 65 out of contact with the opposed side walls of aperture 56, and the shoulders 66 extend astride aperture 56. As previously described in connection with FIG. 6, the T-shaped heads lower notch edges 70 bear against the outer surface 49, when the spring 57 is in its compressed state.

Although the dimensions of aperture 56 are larger than the corresponding dimensions of the tang 65, the tang 65 no longer contacts the opposed longitudinally extending side walls of the aperture 56 as the spring 57 is reciprocated. As shown in FIG. 12, reciprocating motion of the spring shoulders 66, rather than the tang 65, drives the inner cutter 35. Concurrently, the T-shaped head 67 (FIGS. 6 and 7) slidably moves within keyhole aperture 52, the T-shaped head's lower notch edges 70 slidably moving against outer surface 49 as the spring 57 is reciprocated. As a consequence of the lack of relative movement between the springs shoulders 66 and the inner cutter wall 38 when the spring 57 is reciprocated, the inner cutter 35 and spring 57 no longer emit noise as the inner cutter 35 is reciprocated within the outer cutter 17.

It has been found that when the frequency of oscillation of the shaver motor arm 58, and thus the frequency of reciprocation of the inner cutter 35 and spring 57 (FIGS. 7-12), is increased beyond normal operating frequencies of the shaver, the forces exerted by spring shoulders 66 against the recess walls 80 and 81 tend to cause the spring shoulders 66 to slide towards the recess entry opening 77. To insure that there is no sliding during normal operating frequencies, acute angles a and b (FIG. 9) are respectively formed at an angle in the range of from 55 to 85. With the spring configuration shown in FIGS. 7-12, the aforesaid sliding occurs to a greater extent when the inner cutter 35 is driven via recess wall 81, than when the inner cutter 35 is driven via recess wall 80. To compensate for this disparity in sliding tendency and thus further insure that there is no sliding during normal frequencies of operation, acute angle 12 (FIG. 9) is preferably formed at an angle in the range of from to For example, in the embodiment shown in FIGS. 7l2 angle a is about 60 and angle 12 is about 75.

An upper end of another type of electric dry shaver 90, which may be modified by the invention, is shown in FIG. 13. The shaver generally includes a shaver motor (not shown) adapted to oscillate a shaver motor arm 58, and includes an upper portion of a casing 91. The casing 91 includes spaced front and rear walls, respectively designated 92 and 93, and spaced side walls 94. The walls 92, 93 and 94 support a removably mountable cutter head 95 thereon.

The cutter head 95 includes a hollow, rectangularshaped, cutter head body 96, having spaced front and rear walls, respectively designated 97 and 98, and spaced side walls 99. The cutter head 95 also includes a curved stationary outer cutter 100 made of, for example, a thin rectangularly-shaped foil of metal, or of metallic or alloy material. The outer cutter 100 has spaced longitudinally extending side portions 101 and opposed arcuately extending end edges 102, one of each of which is partially shown in FIG. 13. The outer cutter 100 has an inner surface 103 and an outer surface 104 and has plurality spaced apertures 105 formed therein. The apertures 105 provide the inner surface 103 with hair shearing means including a plurality of hair shearing edges 106. The outer cutter 90 is connected to the cutter head body 96 by means well-known in the art. For example, an elongated connecting plate 107 may be provided to cooperate with protrusions 108 extending inwardly from the body 96 of the cutter head 95, to fixedly retain the outer cutter 100, by means of the side portions 101 thereof, in place on the cutter head body 96.

The cutter head 95 also includes a hollow, elongated, movable inner cutter 110 (FIGS. 13 and 14), having a substantially convex semi circuIar appearance in transverse cross-section. The inner cutter 110, which may be made of, for example, a thin rectangularly shaped foil of metal, or of metallic or alloy material, has a semi-circularly curved upper wall 112 and a flat lower wall 38. The upper wall 112 (FIG. 14) has hair shearing means including a plurality of spaced, parallel, transversely extending, hair shearing teeth 114, formed therein by a plurality of spaced parallel slots 115. The hair shearing teeth 114 respectively include opposed hair shearing edges 116.

The parts of the inner cutter lower wall 38 of FIG. 14 bear the same numerical designations as the corresponding parts of the inner cutter wall 38 of FIGS. 2 and 3, and the lower wall 38 of FIG. 14 includes the recess 75 described in connection with FIGS. 7-12. In addition, the spring 57 of FIG. 14 is in all respects the same as the spring 57 shown in FIGS. 2 and 3, and is connected to the lower wall 38 as previously described in connection with FIGS. 712.

Assuming the inner cutter, 110 of FIG. 14 has a spring 57 connected thereto as hereinbefore described in connection with FIGS. 2 and 3, and the inner cutter 110 is mounted by well-known means within the outer cutter 100 of FIG. 13. The cutter head body 96, and thus the cutter head 95, is connected to the shaver casing 91 by, for example, cam means (not shown), within the cutter head body 96, adapted to cooperate with a latch 125 resiliently connected to the shaver casing 11. The shaver motor arm 58 then engages the spring loop 62 to compress the spring 57 towards the inner cutters lower wall 38, thus urging spring 57 from its relaxed state to its compressed state. Compression of the spring urges the inner cutter 110 toward the outer cutter 100 to urge the respective hair shearing edges 116 and 106 to cooperate with one another for shearing hair when the inner cutter 110 is reciprocated within the outer cutter 100.

in accordance with the objects of the invention there has been described an improved inner cutter for a cutter head of an electric dry shaver. In a cutter head including an outer cutter and an inner cutter adapted to be reciprocated within the outer cutter by means of a spring, the inner cutter is provided with means for loosely connecting the spring thereto when the spring is in its relaxed state and means for firmly connecting the spring thereto when the spring is in its compressed state. Thus thecompressed spring is firmly connected to the inner cutter to reciprocate the inner cutter within the outer cutter.

lnasmuch as certain changes may be made in the above described invention without departing from the spirit and scope thereof, it is intended that all matter contained in the'above description or shown in the accompanying drawings shall be interpreted in an illustrative rather than limiting sense. And, it is intended that the following claims be interpreted to cover all the generic and specific features of the invention herein described.

I claim:

1. An improved inner cutter for a shaver of the type which includes an outer cutter and a spring, the cutters each including a first wall having a hair shearing edge and the inner cutter including a second wall, the spring being adapted to be urged from a relaxed state to a compressed state and having opposed end portions, said end portions adapted to be detachably connected to the second wall of the inner cutter, and wherein the connected spring in its compressed state normally urges the hair shearing edge of the inner cutter to cooperate with the hair shearing edge of the outer cutter for shearing hair as the inner cutter is reciprocated within the outer cutter by means of the spring, the improved inner cutter comprising:

a. an aperture formed in said second wall and including opposed walls, said aperture being dimensioned to loosely contain one of the spring end portions within the aperture and permit said one spring end portion to freely contact said aperture walls when the spring is in its relaxed state; and

b. a recess formed in said second wall and including opposed walls, said recess walls being dimensioned to wedge said one spring end portion within said recess and hold said one spring end portion out of contact with said aperture walls when the spring is in its compressed state.

2. The inner cutter according to claim 1, wherein said second wall has inner and outer surfaces, said aperture being dimensioned to permit a first part of said one spring end portion to be received through said second wall from the outer surface thereof and contact the inner surface when the spring is in its relaxed state, and said recess being dimensioned to seat a second part of said spring end portion within said recess and hold said first spring part out of contact withsaid inner surface when the spring is in its compressed state.

3. The inner cutter according to claim 1, wherein said aperture has an entry opening which is elongated and set back within said second wall to form said recess in communication with said aperture, said opposed recess walls extending longitudinally of the length of said recess, and one of said opposed recess walls being inclined towards the other of said opposed recess walls.

4. The inner cutter according to claim 1, for a shaver wherein said speing is a flat spring, a part of said one spring end portion isreduced in width and said spring end portion has at least one shoulder, and wherein said aperture is dimensioned to permit a portion of said spring part to project through said second wall, and said at least one shoulder being wedged within said recess when the spring is in its compressed state.

5. The inner cutter according to claim 1, for a shaver wherein said one spring end portion is reduced in width to provide a tang extending from between a pair of spaced shoulders, and wherein the opposed walls of the recess are elongated and communicate midway of the longitudinal length thereof with said aperture, said tang projecting through said aperture when the spring is connected to the inner cutter, and said shoulders extending astride said aperture and being seated within said recess by means of said opposed recess walls when the spring is in its compressed state.

6. The inner cutter according to claim 1, wherein said opposed recess walls are elongated converging side walls, said recess including an elongated base wall and opposed end walls, said base and end walls merging with said converging side walls, and said aperture merging with said side and base walls approximately midway of the longitudinal length thereof.

7. The inner cutter according to claim 1, for a shaver wherein said one spring end portion is reduced in width and bent to form a bent tang and spaced shoulders, and wherein said second wall of the inner cutter has inner and outer surfaces, a part of the tang overhangs the inner surface of the second wall when the spring is connected to the inner cutter, and said recess walls seat the spring shoulders within said recess when the spring is in its compressed state to thereby locate the spring shoulders within the second wall of the inner cutter for driving engagement therewith.

8. The inner cutter according to claim 1, for a shaver wherein said one spring end portion includes a tang extending from between spaced shoulders, and wherein said recess communicates with said aperture and extends thereacross, said tang extending into the aperture and overhanging a portion of the second wall, and said spring shoulders extending into the recess and alternately exerting driving forces on the opposed recess walls as the spring is reciprocated.

9. The inner cutter according to claim 4, wherein said recess is elongated and said opposed walls thereof are inclined towards one another at angles providing said recess with a truncated wedge shape in transverse cross-section.

10. The inner cutter according to claim 4, wherein another portion of said spring part is disposed within said aperture when the spring is in its compressed state, and said opposed recess walls are inclined towards one another at different angles relative to the plane described by said another portion of said spring part when the spring is in its compressed state.

11. A shaver cutter head comprising:

a. a stationary outer cutter including a first wall having a hair shearing edge,

b. an inner cutter removably mounted for reciprocation within the outer cutter and including first and second walls with the first wall having a hair shearing edge and the second wall having an aperture and a recess formed therein,

c. a spring having opposed end portions detachably connected to the second wall of the inner cutter and the spring adapted to be urged from a relaxed state to a compressed state, and

d. the aperture in the second wall of the inner cutter including opposed walls, said aperture being dimensioned to loosely contain one of said connected spring end portions and to permit said one spring end portion to freely contact said aperture walls when the spring is in its relaxed state, the recess in the second wall including opposed walls dimensioned to wedge said one spring end portion within said recess and hold said one spring end portion out of contact with said aperture walls when the spring is in its compressed state, and the spring under compression urging the inner cutter hair shearing edge to cooperate with the outer cutter hair shearing edge for shearing hair as the inner cutter is reciprocated within the outer cutter by means of the spring.

12. The shaver cutter head according to claim 11, wherein said spring is a flat spring, a part of said one spring end portion is reduced in width and said spring has at least one shoulder, the aperture in the second wall of the inner cutter being dimensioned to loosely receive said spring part of reduced width, and at least one of said recess walls converges towards the other of said recess walls to wedge said at least one spring shoulder within said recess to firmly connect said one spring end portion to the second wall of the inner cutter for reciprocation of the inner cutter within the outer cutter.

13. The shaver cutter head according to claim 11, wherein the opposed walls of said recess communicate with said aperture and at least one of said opposed walls, is inclined toward the other of said opposed walls, a part of said one spring end portion is reduced in width to form a tang extending from between a pair of spaced shoulders, said tang projecting at least partially through said aperture and said shoulder being wedged between said opposed recess walls by said spring under compression, and said spring shoulders exerting driving forces against the opposed recess walls as the inner cutter is reciprocated within the outer cutter by means of the spring. 

1. An improved inner cutter for a shaver of the type which includes an outer cutter and a spring, the cutters each including a first wall having a hair shearing edge and the inner cutter including a second wall, the spring being adapted to be urged from a relaxed state to a compressed state and having opposed end portions, said end portions adapted to be detachably connected to the second wall of the inner cutter, and wherein the connected spring in its compressed state normally uRges the hair shearing edge of the inner cutter to cooperate with the hair shearing edge of the outer cutter for shearing hair as the inner cutter is reciprocated within the outer cutter by means of the spring, the improved inner cutter comprising: a. an aperture formed in said second wall and including opposed walls, said aperture being dimensioned to loosely contain one of the spring end portions within the aperture and permit said one spring end portion to freely contact said aperture walls when the spring is in its relaxed state; and b. a recess formed in said second wall and including opposed walls, said recess walls being dimensioned to wedge said one spring end portion within said recess and hold said one spring end portion out of contact with said aperture walls when the spring is in its compressed state.
 2. The inner cutter according to claim 1, wherein said second wall has inner and outer surfaces, said aperture being dimensioned to permit a first part of said one spring end portion to be received through said second wall from the outer surface thereof and contact the inner surface when the spring is in its relaxed state, and said recess being dimensioned to seat a second part of said spring end portion within said recess and hold said first spring part out of contact with said inner surface when the spring is in its compressed state.
 3. The inner cutter according to claim 1, wherein said aperture has an entry opening which is elongated and set back within said second wall to form said recess in communication with said aperture, said opposed recess walls extending longitudinally of the length of said recess, and one of said opposed recess walls being inclined towards the other of said opposed recess walls.
 4. The inner cutter according to claim 1, for a shaver wherein said speing is a flat spring, a part of said one spring end portion is reduced in width and said spring end portion has at least one shoulder, and wherein said aperture is dimensioned to permit a portion of said spring part to project through said second wall, and said at least one shoulder being wedged within said recess when the spring is in its compressed state.
 5. The inner cutter according to claim 1, for a shaver wherein said one spring end portion is reduced in width to provide a tang extending from between a pair of spaced shoulders, and wherein the opposed walls of the recess are elongated and communicate midway of the longitudinal length thereof with said aperture, said tang projecting through said aperture when the spring is connected to the inner cutter, and said shoulders extending astride said aperture and being seated within said recess by means of said opposed recess walls when the spring is in its compressed state.
 6. The inner cutter according to claim 1, wherein said opposed recess walls are elongated converging side walls, said recess including an elongated base wall and opposed end walls, said base and end walls merging with said converging side walls, and said aperture merging with said side and base walls approximately midway of the longitudinal length thereof.
 7. The inner cutter according to claim 1, for a shaver wherein said one spring end portion is reduced in width and bent to form a bent tang and spaced shoulders, and wherein said second wall of the inner cutter has inner and outer surfaces, a part of the tang overhangs the inner surface of the second wall when the spring is connected to the inner cutter, and said recess walls seat the spring shoulders within said recess when the spring is in its compressed state to thereby locate the spring shoulders within the second wall of the inner cutter for driving engagement therewith.
 8. The inner cutter according to claim 1, for a shaver wherein said one spring end portion includes a tang extending from between spaced shoulders, and wherein said recess communicates with said aperture and extends thereacross, said tang extending into the aperture and overhanging a portion of the second wall, and said spring shoulders extending into the recess and alternately exerting driving forces on the opposed recess walls as the spring is reciprocated.
 9. The inner cutter according to claim 4, wherein said recess is elongated and said opposed walls thereof are inclined towards one another at angles providing said recess with a truncated wedge shape in transverse cross-section.
 10. The inner cutter according to claim 4, wherein another portion of said spring part is disposed within said aperture when the spring is in its compressed state, and said opposed recess walls are inclined towards one another at different angles relative to the plane described by said another portion of said spring part when the spring is in its compressed state.
 11. A shaver cutter head comprising: a. a stationary outer cutter including a first wall having a hair shearing edge, b. an inner cutter removably mounted for reciprocation within the outer cutter and including first and second walls with the first wall having a hair shearing edge and the second wall having an aperture and a recess formed therein, c. a spring having opposed end portions detachably connected to the second wall of the inner cutter and the spring adapted to be urged from a relaxed state to a compressed state, and d. the aperture in the second wall of the inner cutter including opposed walls, said aperture being dimensioned to loosely contain one of said connected spring end portions and to permit said one spring end portion to freely contact said aperture walls when the spring is in its relaxed state, the recess in the second wall including opposed walls dimensioned to wedge said one spring end portion within said recess and hold said one spring end portion out of contact with said aperture walls when the spring is in its compressed state, and the spring under compression urging the inner cutter hair shearing edge to cooperate with the outer cutter hair shearing edge for shearing hair as the inner cutter is reciprocated within the outer cutter by means of the spring.
 12. The shaver cutter head according to claim 11, wherein said spring is a flat spring, a part of said one spring end portion is reduced in width and said spring has at least one shoulder, the aperture in the second wall of the inner cutter being dimensioned to loosely receive said spring part of reduced width, and at least one of said recess walls converges towards the other of said recess walls to wedge said at least one spring shoulder within said recess to firmly connect said one spring end portion to the second wall of the inner cutter for reciprocation of the inner cutter within the outer cutter.
 13. The shaver cutter head according to claim 11, wherein the opposed walls of said recess communicate with said aperture and at least one of said opposed walls, is inclined toward the other of said opposed walls, a part of said one spring end portion is reduced in width to form a tang extending from between a pair of spaced shoulders, said tang projecting at least partially through said aperture and said shoulder being wedged between said opposed recess walls by said spring under compression, and said spring shoulders exerting driving forces against the opposed recess walls as the inner cutter is reciprocated within the outer cutter by means of the spring. 